using System;
using System.Collections.Generic;
using System.Text;

#if (XNA)
using Microsoft.Xna.Framework; 
#endif

namespace FarseerGames.FarseerPhysics.Mathematics {
    public class ConvertUnits {
        private static float _displayUnitsToSimUnitsRatio = 50;
        private static float _simUnitsToDisplayUnitsRatio = 1 / _displayUnitsToSimUnitsRatio;

        public static void SetDisplayUnitToSimUnitRatio(float displayUnitsPerSimUnit) {
            _displayUnitsToSimUnitsRatio = displayUnitsPerSimUnit;
            _simUnitsToDisplayUnitsRatio = 1 / displayUnitsPerSimUnit;
        }

        public static float ToDisplayUnits(float simUnits) {
            return simUnits * _displayUnitsToSimUnitsRatio;
        }

        public static float ToSimUnits(float displayUnits) {
            return displayUnits * _simUnitsToDisplayUnitsRatio;
        }

        public static float ToSimUnits(double displayUnits)
        {
            return (float)displayUnits * _simUnitsToDisplayUnitsRatio;
        }

        public static float ToDisplayUnits(int simUnits) {
            return (float)simUnits * _displayUnitsToSimUnitsRatio;
        }

        public static float ToSimUnits(int displayUnits) {
            return (float)displayUnits * _simUnitsToDisplayUnitsRatio;
        }

        public static Vector2 ToDisplayUnits(Vector2 simUnits) {
            return _displayUnitsToSimUnitsRatio * simUnits;
        }

        public static void ToDisplayUnits(ref Vector2 simUnits, out Vector2 displayUnits) {
            Vector2.Multiply(ref simUnits, _displayUnitsToSimUnitsRatio, out displayUnits);
        }

        public static Vector2 ToDisplayUnits(float x, float y) {
            return _displayUnitsToSimUnitsRatio * new Vector2(x, y);
        }

        public static void ToDisplayUnits(float x, float y, out Vector2 displayUnits) {
            displayUnits = Vector2.Zero; 
            displayUnits.X = x * _displayUnitsToSimUnitsRatio;
            displayUnits.Y = y * _displayUnitsToSimUnitsRatio;
        }

        public static Vector2 ToSimUnits(Vector2 displayUnits) {
            return _simUnitsToDisplayUnitsRatio * displayUnits;
        }

        public static void ToSimUnits(ref Vector2 displayUnits, out Vector2 simUnits) {
            Vector2.Multiply(ref displayUnits, _simUnitsToDisplayUnitsRatio, out simUnits);
        }

        public static Vector2 ToSimUnits(float x, float y) {
            return _simUnitsToDisplayUnitsRatio * new Vector2(x, y);
        }

        public static Vector2 ToSimUnits(double x, double y)
        {
            return _simUnitsToDisplayUnitsRatio * new Vector2((float)x, (float)y);
        }
        
        public static void ToSimUnits(float x, float y, out Vector2 simUnits) {
            simUnits = Vector2.Zero;
            simUnits.X = x*_simUnitsToDisplayUnitsRatio;
            simUnits.Y = y * _simUnitsToDisplayUnitsRatio;
        }

    }
}
